lkml.org 
[lkml]   [2014]   [Nov]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v3 2/2] mem-hotplug: Reset node present pages when hot-adding a new pgdat.
Date
When memory is hot-added, all the memory is in offline state. So
clear all zones' present_pages because they will be updated in
online_pages() and offline_pages(). Otherwise, /proc/zoneinfo
will corrupt:

When the memory of node2 is offline:
# cat /proc/zoneinfo
......
Node 2, zone Movable
......
spanned 8388608
present 8388608
managed 0

When we online memory on node2:
# cat /proc/zoneinfo
......
Node 2, zone Movable
......
spanned 8388608
present 16777216
managed 8388608

Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: stable@vger.kernel.org # 3.16+
---
mm/memory_hotplug.c | 17 +++++++++++++++++
1 file changed, 17 insertions(+)

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 8aba12b..d0c9b7c 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1067,6 +1067,16 @@ out:
}
#endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */

+static void reset_node_present_pages(pg_data_t *pgdat)
+{
+ struct zone *z;
+
+ for (z = pgdat->node_zones; z < pgdat->node_zones + MAX_NR_ZONES; z++)
+ z->present_pages = 0;
+
+ pgdat->node_present_pages = 0;
+}
+
/* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */
static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start)
{
@@ -1105,6 +1115,13 @@ static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start)
*/
reset_node_managed_pages(pgdat);

+ /*
+ * When memory is hot-added, all the memory is in offline state. So
+ * clear all zones' present_pages because they will be updated in
+ * online_pages() and offline_pages().
+ */
+ reset_node_present_pages(pgdat);
+
return pgdat;
}

--
1.8.3.1


\
 
 \ /
  Last update: 2014-11-12 10:21    [W:0.036 / U:2.896 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site